The use of thermoformable plastic such as polyethylene terephthalate (PET) for packaging has risen sharply in recent years, replacing glass and aluminum in many applications. To manufacture the thermoformable plastic containers, plastic, in the form of sheets, is heated, formed and then trimmed from the sheet. To facilitate trimming, the plastic around the article being trimmed is often heated prior to trimming. One type of trimming system that is employed uses a steel-rule die in which a knife blade that is held in a wooden board is brought into contact with a heated striker plate to sever the plastic article from the sheet of plastic. While the steel-rule die is relatively inexpensive and provides satisfactory cutting characteristics, steel rule dies are less durable than more costly die alternatives such as machined tool steel dies and forged dies. This is because the steel-rule is susceptible to damage from the pressure between the cutting edge and the striker plate. A typical steel-rule die has a life of 5,000 strikes before it must be replaced or sharpened.